Persistent Self-Induced Larmor Precession Evidenced through Periodic Revivals of Coherence

Interferometric measurements of an optically trapped exciton-polariton condensate reveal a regime where the condensate pseudo-spin precesses persistently within the driving optical pulse. For a single 20 mu s optical pulse, the condensate pseudo-spin undergoes over 10(5) full precessions with striking frequency stability. The emergence of the precession is traced to polariton nonlinear interactions that give rise to a self-induced out-of-plane magnetic field, which in turn drives the system spin dynamics. The Larmor precession frequency and trajectory are directly influenced by the condensate density, enabling the control of this effect with optical means. Our results accentuate the system's potential for the realization of magnetometry devices and can lead to the emergence of spin-squeezed polariton condensates.

Automated summary

Interferometric measurements of an optically trapped exciton-polariton condensate show persistent precession of the condensate pseudo-spin within the driving optical pulse. The precession frequency and trajectory can be controlled by the condensate density using optical means. This discovery highlights the potential for magnetometry devices and the emergence of spin-squeezed polariton condensates.